An audio spectrum analyzer (hereinafter referred to as “spectrum analyzer”) is used for breaking down an audio signal into its individual audio frequency components. It is an important tool for audio recording engineers in analyzing and correcting the sound balance of an audio source. The result of the spectrum analyzer is normally represented by numerous rows of LEDs that represent the peak level input of a particular frequency band at a particular time. Each row of LEDs is driven by a circuit that has been tuned to pick up a particular frequency band in the audio spectrum, and each circuit lights up its respective LEDs according to the energy quantum of the signal received. As an audio signal is being fed into the spectrum analyzer, the rows of LEDs spike dynamically with every change in the audio signal.
Although the function of a spectrum analyzer is redundant in non-professional, consumer AV products like compact disc players, DVD players, TVs etc., the nature of representation of the spectrum analyzer adds a distinctive visual appeal to these products, as these products have conventionally contained mostly static, non-dynamic indicators.
Over the years, the spectrum analyzer has been incorporated into a multitude of AV products to increase their visual appeal to consumers. However, a spectrum analyzer circuit is very complex. So, the incorporation of the spectrum analyzer feature generally adds unnecessary cost, weight and dimension to a product. Therefore, from the production cost point of view, it is feasible only to incorporate spectrum analyzers into high-end, expensive electronics where the cost of incorporating the circuit is small compared to the cost of producing the electronics. Also, a stand-alone display for a spectrum analyzer consumes unnecessary space available for today's consumer AV products, which are getting more compact and smaller in size.
Product designers are constantly being demanded to introduce new attractive packaging and layouts to existing technologies to renew their marketability, without incurring unnecessary additional cost to the manufacturing processes.
U.S. Pat. No. 6,167,139 discloses an apparatus for controlling and outputting the volume and tone of a sound signal, which also contains an on-screen processor for outputting data superimposed on an image signal.